Multi-voice unison note heads jump

1. Start a new score for treble-staff
2. Add a quarter-note B (center line) to voice one
3. Add a quarter-note B (center line) to voice two
4. Press "N" to leave note entry
5. Double-click on note head (Expected behavior at this point is for the note head to turn green)
6. Press the left arrow key about five times to move the note head to one side
7. Press Esc to leave note-head edit mode

Expected behavior: note head to move to the position indicated

Actual behavior: note head moves about the width of a note head further than the position indicated.